Answer:
Caesar August of Roman Empire
Right now, I would call them "diaspora" if they're more dispersed (Armenian diaspora is quite well-known) or a "community", for example "French community" if they're more closely in contact.
If they reject their new land's law and intend to include this land into their old one, they could be "colonizers".
One way thing that the US could do about monopies is regulating them by breaking a monopoly up. In certain cases, government may decide a monopoly needs to be broken up because the firm has become too powerful. This rarely occurs. For example, the US looked into breaking up Microsoft, but in the end the action was dropped. This tends to be seen as an extreme step, and there is no guarantee the new firms won’t collude.